For example, a mounting machine for mounting an electronic component on a board includes an electronic component clamping device for clamping an electronic component. Generally, the electronic component clamping device includes a pair of claws arranged facing each other, and an opening/closing mechanism for opening and closing the pair of claws. The pair of claws contact a pair of side faces of an electronic component to clamp the electronic component. The opening/closing mechanism moves the pair of claws to a first position to clamp the electronic component and a second position to release the electronic component. When the electronic component is mounted on a board, the electronic component clamping device is moved with respect to the electronic component in a state in which the pair of claws is fixed at the second position. Thereafter, the pair of claws is moved to the first position, and the pair of claws clamps the electronic component. By moving the electronic component clamping device with the electronic component clamped, the electronic component is moved to a mounting position of the board. When the electronic component has been moved to the mounting position, the pair of claws is moved to the second position and the electronic component is released. Thus, the electronic component is mounted on the board.
Multiple types of electronic components are clamped with this type of electronic component clamping device. Sizes of electronic components may vary by having electronic components of different types. In order to clamp electronic components of different sizes with the same electronic component clamping device, the distance between the pair of claws may be varied. Then, the electronic component is clamped between the pair of claws whose distance is changed. This makes it possible to clamp multiple types of electronic components with one electronic component clamping device. As a technique for mounting components of different sizes using the same device, for example, there is a seal ring assembling device disclosed in Patent Literature 1.